Methylotrophic bacteria affect our existence in many ways: they form a vital link in the carbon cycle, strongly affecting the quality of water systems, they are capable of detoxifying halogenated compounds in the environment, and they have tremendous biotechnological potential. This important group of organisms is currently under intensive study, but the understanding of their metabolism has been hampered by the lack of genetics. We have now identified mutagenesis and gene transfer systems that are functional in a variety of methylotrophic bacteria. We propose to use these techniques to carry out a comprehensive study of the genetic regulation of C-1 specific functions. First, we will identify C-1 specific polypeptides on two dimensional polyacrylamide gels using a combination of activity stains and mutant analyses. Second, using cloned DNA that complements each mutant, we will identify the genetic locus of each C-1 specific polypeptide. And finally, using a chemostat, we will study the regulation of the identified polypeptides by growth rate, carbon source and dissolved oxygen tension.